In the production of edible ice cream products, it is well-known to use so-called through-flow freezers comprising a freezing cylinder in which a mixture of so-called ice cream mix (also known just as “mix”) and air is frozen to ice cream by cooling the freezing cylinder from its outside using a liquid coolant such as, for instance, ammonia (NH3), carbon dioxide (CO2) or some sort of Freon. The ice cream mass is typically transported through the freezing cylinder by pumping.
During start-up of such systems, the freezing cylinder is normally filled at least partly with mix before it is cooled down. After filling the freezing cylinder, the cooling is started and runs for some time, while the mixture of mix and air is whipped or stirred inside the freezing cylinder.
When predefined values of some parameters of this first batch of ice cream inside the freezing cylinder have been reached, the continuous production is started by pumping frozen ice cream out of from one end the freezing cylinder and pumping new mix and air into the other end of the freezing cylinder. This changes the composition of the ice cream mass in the freezing cylinder and, thereby, also the values of different parameters thereof. It takes a certain amount of time, typically several minutes, before the continuous production is stable in the sense that the desired values of such parameters have been reaches. The frozen ice cream produced during this time is typically wasted but may, under certain circumstances, be fed back into the system and reused in the continuous production process.
It is an object of the present invention to provide an improved through-flow freezer and a more effective start-up procedure, which can be used with such a through-flow freezer for reducing the time consumed and the amount of waste ice cream produced until stable conditions for the continuous production have been reached.